The best studied animal models for ARS are mice, canines, and non-human primates (NHP). An alternative large animal model would be advantageous for countermeasure development, to provide flexibility in matching compounds to a suitable species in terms of pharmacological parameters. Swine are increasingly used in drug development because of the similarity of their anatomy and physiology to those of humans. We demonstrate here the Gottingen minipig is a viable model in terms of practicality of whole-body gamma-irradiation, reliability of serial blood sampling from unanesthetized animals, and responses to ionizing radiation similar to what is observed in canines, NHP, and humans.